1 files changed, 34 insertions, 0 deletions
diff --git a/tools/mkinitrd.c b/tools/mkinitrd.c
new file mode 100644
index 0000000..d61bbba
--- /dev/null
+++ b/tools/mkinitrd.c
@@ -0,0 +1,34 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+void write_le32(int fd, uint32_t n)
+{
+    write(fd, &n, 4);
+}
+
+#define MIN(x,y) (x<y?x:y)
+
+int main(int argc, char* argv[])
+{
+    int fd = open("initrd.img", O_APPEND | O_WRONLY | O_CREAT, 0666);
+    char buf[32];
+    assert(strlen(argv[1]) < 32);
+    memset(buf, 0, 32);
+    memcpy(buf, argv[1], strlen(argv[1]));
+    write(fd, buf, 32);
+    int datafd = open(argv[1], O_RDONLY, 0666);
+    lseek(datafd, 0, SEEK_END);
+    FILE *f = fdopen(datafd, "rb");
+    uint32_t len = ftell(f);
+    write_le32(fd, ftell(f));
+    int ch;
+    lseek(datafd, 0, SEEK_SET);
+    do {
+        ch = getc(f);
+        if(ch != EOF)
+            write(fd, &ch, 1);
+    } while(ch != EOF);
+}